This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2001-326153, filed Oct. 24, 2001; and No. 2001-326154, filed Oct. 24, 2001, the entire contents of both of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a junction box including connecting terminals for electrically connecting a connector, fuse, and the like to a wiring circuit, and particularly to a junction box which is lightweight and thin, can freely change connection positions with outer wiring circuits such as a harness and can enhance a wiring design freedom degree.
2. Description of the Related Art
In general, to branch a wiring of a car or the like, a junction box (J/B) has been used for purposes of space saving and cost reduction. FIG. 14 is a plan view of the junction box, FIG. 15 is a plan view of a bus bar contained in the junction box, FIG. 16 is a sectional view of a part VII of FIG. 14, and FIG. 17 is a sectional view of a part VIII of FIG. 14.
This type of a junction box 101 is constituted of a lower cover 102, a bus bar 103 attached to the lower cover 102, and an upper cover 105 which seals the lower cover and bus bar and to which a connector, fuse, and the like are attached. In the junction box 101, as shown in FIG. 15, the bus bar 103 formed, for example, of a pressed/punched metal plate of copper alloy, aluminum alloy, or the like is used to branch the wiring. Moreover, the junction box 101 also includes a function, for example, of a fuse box, when a fuse 107 is incorporated halfway in the wiring circuit constituted by the bus bar 103.
A connector 107 shown in FIG. 16 is a connector connected to the wiring circuit constituted of the bus bar 103. A connector 105a can be connected to the connector 107, when a connecting terminal portion 103a formed by bending a tip end of the bus bar 103 upwards by 90xc2x0 is passed upwards through an upper cover 105 via a through hole 105b formed in the cover. Moreover, for a fuse attachment portion 105c to which a fuse 108 is attached as shown in FIG. 17, a connecting terminal portion 103d is formed by bending the tip end of the bus bar 103 with a slit 103b formed therein upwards by 90xc2x0, and is passed upwards through the upper cover 105 through a through hole 105d formed in the cover. Thereby, the connecting terminal portion can directly be connected to a leg 108a for connecting the fuse 108, or can be connected using a so-called female to female (Fxe2x80x94F) terminal.
Moreover, as shown in FIG. 18, the bus bars 103 and insulation plates (IP) 109 having functions of supporting and insulating the bus bars 103 are alternately superimposed to form a wiring circuit (multilayered wiring circuit) 110 which has a multilayered structure. A junction box 112 structured to contain the multilayered wiring circuit 110 in a housing for entirely protecting the outside of the circuit as shown in FIG. 19 is frequently used.
However, in the above-described junction box 101, the bus bar 103 is manufactured by punching the metal plate with a die and the wiring circuit is formed. Therefore, when the bus bars 103 having various shapes are manufactured, different dies are required, and much cost is taken. Moreover, the bus bar 103 is formed of a thick metal, a weight of the junction box 101 therefore increases, and there is a problem that it is difficult to thin the junction box 101. Furthermore, in the junction box 112, the number of layers of the multilayered wiring circuit 110 needs to be minimized in order to prevent the weight and cost of the entire junction box from increasing. Additionally, the multilayered wiring circuit 110 having a small number of layers is used in accordance with a connection mode. For this, a circuit is drawn so as to avoid a wiring circuit of another layer and through holes 111 through which the connecting terminal portions 103a, 103d are passed, and a long circuit needs to be formed. This causes a problem that it is very difficult to lighten and thin the junction box 112.
Furthermore, when the bus bar 103 is used to form a multilayered wiring circuit having more layers, for example, the type of the bus bar 103 increases, and the cost of a metal mold increases. Therefore, it is difficult to realize a high-density wiring. As a result, a problem occurs that a freedom degree of wiring design of the junction box is restricted.
An object of the present invention is to provide a junction box in which weight saving and thinning are realized and a freedom degree of wiring design can be enhanced.
According to an aspect of the present invention, the object is achieved by providing a junction box comprising: a junction box main body to which an electric component to be connected is attached; a connector portion which connects a connector of an outer wiring circuit and a joint connector of a circuit distribution wiring circuit and is formed separately from the junction box main body; and a cable portion which is constituted of a flexible printed circuit with a circuit portion including a conductor pattern formed on an insulating film, and electrically connects the junction box main body to the connector portion, wherein the flexible printed circuit includes: a strip portion which connects the junction box main body to the connector portion; and a terminal connecting portion extending from a side edge of a position of the strip portion in which the junction box main body and connector portion are arranged in a short direction of the strip portion,
the junction box main body includes: a junction box housing including a component attachment port to which the electric component to be connected is attached; and a plate-shaped first connecting terminal which is connected to the terminal connecting portion of the flexible printed circuit and contained in the junction box housing so as to be connected to the electric component to be connected, and the connector portion includes: a connector housing which is engaged with at least one of the connector of the outer wiring circuit and the joint connector of the circuit distribution wiring circuit; a plate-shaped second connecting terminal which is connected to the terminal connecting portion of the flexible printed circuit and contained in the connector housing so as to be connected to the connector of the outer wiring circuit; and a plate-shaped third connecting terminal which is connected to the terminal connecting portion of the flexible printed circuit and contained in the connector housing so as to be connected to the joint connector of the circuit distribution wiring circuit.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.